Gjøvik University College Cryptology 1

4 Conclusion

The Hagelin M-209 was a very advanced ciphering machine, ahead of its time. The fact that it was fully mechanical, was an amazing achievement. In addition the M-203 was very small, rugged and able to perform both enciphering and deciphering which made it perfect for tactical use. But one thing to think about today, is how much work it was to change the internal ciphering key, compared to how easily this can be done on today’s crypto equipment. I can’t imagine how frustrating this could be for soldiers in the field, with bullets flying around them. But I guess this was the reason keys most often were changed once a day.

The machine built on principles from the early 1920s, and was improved to the last rotor machine from Boris Hagelin, the CX-52, which still today is hard to decrypt by an adversary. One interesting thing today, after the Snowden leakage on NSA backdoors, is that they already had backdoors as early as in 1957 in the CX-52.

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The Hagelin M-209 cipher machine